Fuel consumption can be reduced by shutting down one of the twin engines during portions of the mission or flight when one engine provides sufficient power.
During take-off and landing, both of the twin engines may be utilized for safety and to ensure adequate power. While in flight, a single engine may provide sufficient power and fuel savings can be achieved by shutting down one engine. One highly loaded engine consumes less fuel than two lightly loaded engines, thereby resulting in net fuel savings.
Rapid reactivation of the dormant engine may be required if the other engine fails, or if additional power is required in flight. An independent rapid starting system is desirable to safely enable single engine operation.